Method for finishing a substrate of the semiconductor-on-insulator type

A method for forming a semiconductor-on-insulator (SeOI) type substrate including an insulator layer buried between a layer of semiconducting material and a support, the method comprising:

• introducing the SeOI type substrate into the enclosure including a circular lower electrode surrounded by an annular lower insulating element and a disk-shaped upper insulating element surrounded by a ring-shaped upper electrode;
• positioning a rear face of the SeOI type substrate on the circular lower electrode and the lower insulating element;
• positioning the disk-shaped upper insulating element a distance from the front face of the SeOI type substrate;
• depositing a protective material on a peripheral annular area of the SeOI type substrate using plasma generated with the circular lower electrode and the ring-shaped upper electrode while the disk-shaped upper insulating element is positioned at the first distance from the front face of the SeOI type substrate;
• moving the disk-shaped upper insulating element closer to the front face of the SeOI type substrate and removing a portion of the protective material using plasma generated with the circular lower electrode and the ring-shaped upper electrode;
• removing a portion of the layer of semiconducting material and a portion of the insulator layer at the annular periphery of the SeOI type substrate laterally beyond a remaining ring of the protective material using plasma generated with the circular lower electrode and the ring-shaped upper electrode;
• and
• removing the remaining ring of protective material after removing the portion of the layer of semiconducting material and the portion of the insulator layer at the annular periphery of the SeOI type substrate.